Mr Bharara, the 48-year-old scourge of Wall Street philanderers, terrorists and corrupt politicians alike, announced on Saturday that he had been fired, having refused a Friday night order that all 46 Obama-era attorneys resign.

I did not resign. Moments ago I was fired. Being the US Attorney in SDNY will forever be the greatest honor of my professional life.

It is not unusual to ask for politically-appointed prosecutors to resign: however, they have not previously been ordered to leave their posts immediately. And Mr Bharara had been given assurances that he would be allowed to continue in his role.

The India-born lawyer was invited by Mr Trump to Trump Tower in November and appeared before cameras to give a statement that he had been asked to continue in his role as prosecutor for the southern district of New York. He said that Jeff Sessions, the incoming attorney general, had agreed.

The New York Times reported that on Thursday Mr Trump’s assistant attempted to reach Mr Bharara, asking that the prosecutor return the call.

Mr Bharara consulted his staff and determined that it would probably be a violation of justice department protocols for him to speak directly to the president.

Mr Bharara instead informed Mr Sessions’s office that he would not be returning the call because of protocols curtailing a president’s contact with federal prosecutors. He then rang Mr Trump’s assistant to also explain why he could not speak to the president.

Many were shocked at the brutal nature of the turnover. They were given no warning, with Mr Sessions signing off on a phone call with them all on Thursday with the words: “Happy hunting!”

On Friday afternoon they were informed that they must step aside, and told to clear their desks by midnight.

It is not known why Mr Trump wanted to speak to Mr Bharara on Thursday – whether it was to inform him of the impending cull, and that he had changed his mind about allowing him to stay, or for another reason.

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U.S. President Donald J. Trump speaks during a discussion on healthcare in the Roosevelt room of the White House - Credit: UPI / Barcroft Images

On Saturday afternoon Mr Bharara sent an email to his staff, emphasising that he did not regisn.

“Needless to say it is personally very sad for me,” the note said.

“This is the greatest place on Earth and I love you all. Even on a day when your US Attorney gets fired it is still Thanksgiving because you all still get to do the most honorable work there is to do.”

Mr Bharara added that the office “could not be in better hands” than with the deputy US attorney for the Southern District of New York, Joon H. Kim, whom he called “a tremendous leader and public servant and who loves the office just as much as I do.”

Mr Bharara was currently investigating the mayor of New York, Bill de Blasio, over campaign funding and aides to the governor of New York, Andrew Cuomo.

The New York Post on Sunday featured a picture of Mr de Blasio “celebrating” – with a glass of champagne photoshopped into his hand and a party hat on his head.

“Preety happy,” was the headline, with the phrase: “Xmas comes early for de Blasio as Trump fires foe Bharara.”

The cases investigated by Mr Bharara will now be overseen by his deputies, until a replacement is appointed.

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Former New York City Mayor Rudy Giuliani arrives at Trump Tower

He was also overseeing a probe into Fox News’s handling of sexual harassment allegations, and prosecuting Ahmad Rahimi, the New York bomber. Any investigation involving Trump Tower would have to pass through his office – although there is no evidence that any such investigation is ongoing.

And Mr Bharara, featured in magazines, nicknamed "The Sheriff of Wall Street" and described as "a rockstar" of prosecutors, is unlikely to fade from view.

Previous prosecutors for the district have included Rudy Giuliani, who went on to be mayor of New York, and James Comey, current FBI director.